compiler/rustc_error_codes/src/error_codes/E0445.md

   1 A private trait was used on a public type parameter bound.
   2
   3 Erroneous code examples:
   4
   5 ```compile_fail,E0445
   6 #![deny(private_in_public)]
   7
   8 trait Foo {
   9     fn dummy(&self) { }
  10 }
  11
  12 pub trait Bar : Foo {} // error: private trait in public interface
  13 pub struct Bar2<T: Foo>(pub T); // same error
  14 pub fn foo<T: Foo> (t: T) {} // same error
  15
  16 fn main() {}
  17 ```
  18
  19 To solve this error, please ensure that the trait is also public. The trait
  20 can be made inaccessible if necessary by placing it into a private inner
  21 module, but it still has to be marked with `pub`. Example:
  22
  23 ```
  24 pub trait Foo { // we set the Foo trait public
  25     fn dummy(&self) { }
  26 }
  27
  28 pub trait Bar : Foo {} // ok!
  29 pub struct Bar2<T: Foo>(pub T); // ok!
  30 pub fn foo<T: Foo> (t: T) {} // ok!
  31
  32 fn main() {}
  33 ```